get_mappings: Transforming a mapping (transition) table to two associative lists
Description
to rearrange the one classification encoding into another,
an associative list that maps keys to values is used.
More precisely, an association list is used which is a linked list in which
each list element consists of a key and value or values.
An association list where unique categories codes are keys and matching
categories from next or previous time point are values.
A mapping (transition) table is used to build such associative lists.
Usage
get_mappings(x = data.frame())
Value
a list with 2 named lists `to_old` and `to_new`.
Arguments
x
`data.frame` or `matrix` - mapping (transition) table with 2 columns
where first column is assumed to be the older encoding.